The present invention relates to the equipment to be used for intensification of physical and chemical processes of affecting the structure of bodies placed in a liquid phase, and more particularly, it relates to an apparatus for creating acoustic oscillations in a running liquid medium to be used mainly for dispergation, emulsification and coagulation of emulsions, solutions, suspensions or homogeneous liquids.
Various apparatus are used for these purposes which create sonic and ultrasonic oscillations in liquid media including those in which the main elements for creating a wave process comprise a rotating rotor and a fixed stator having passages or conduits therein. These apparatus are being permanently improved so as to separate the fundamntal frequency from noises generated due to the caviation phenomenon and to increase the efficiency. The application of such apparatus is, however, limited due to the fact that the frequency of generated oscillations lies predominantly in the low frequency range.
Known in the art is an apparatus for creating acoustic oscillations in a running liquid medium comprising a working chamber accommodating a stator made in the form of a hollow cylinder having a row of apertures in the peripheral surface and a rotor connected to a drive, coaxial with the stator and having a row of apertures in the peripheral surface, a number of apertures of the rotor being by a whole number of times greater than the number of apertures in the stator, and when the apertures of the rotor are brought in register with the apertures of the stator at regular time intervals, the liquid medium admitted to the internal space of the rotor penetrates the working chamber.
In the above-described apparatus the rotor shaft is connected with a rotary drive. The working chamber and the stator are made integral and are closed with a cover having an inlet opening and an outlet openings so that the working chamber comprises a closed space communicating with the internal space of the rotor through the apertures of the stator and rotor and spaces therebetween. Liquid medium is admitted to the internal space of the rotor and is pressed through the apertures of the rotor, space between the rotor and stator, and apertures of the stator into the working chamber having the outlet opening.
The apertures of the stator and rotor are made in the form of slits so that the solid portions between the apertures comprise rods having one end integral with the body of the stator or rotor. It should be noted that the rotor and stator are made with one or several walls and are mounted coaxially relative to each other so that the open end of the stator faces the open end of the rotor, or the end wall of the rotor faces the open end of the stator.
Generation of acoustic oscillations in the above-described apparatus occurs during the rotation of the rotor with the running liquid medium contained in the internal space or spaces thereof, while the row of apertures in the combination rotor/stator are brought in and out of register at regular intervals so that the flow of liquid medium through the apertures is interrupted, while the flow of liquid medium in the rotor and stator remains continuous. With such flow conditions of the running liquid medium, acoustic oscillations are generated in the apparatus, and hydrodynamic cavitation over a large range of acoustic frequencies also develops, said oscillations being transmitted into the working chamber and internal space of the rotor in the form of acoustic pressure waves.
However, this construction of an apparatus for creating (generating) acoustic oscillations in a running liquid medium is rather inefficient for physical and chemical processes of homogenization, dispergation and emulcification. This is due to the fact that the oscillations have a continuous frequency spectrum inherent in hydrodynamic cavitation in a liquid medium. For effecting a specific physical and chemical process powerful acoustic oscillations are required with a selected fundamental frequency corresponding to the optimal conditions of the process. Not only the oscillations are to be provided in the rotor and stator apertures, but they are more important in the internal space or spaces of the rotor and in the working chamber, wherein the major mass of the "sound treated" medium is concentrated. Besides, the cavitation process itself occurring in a liquid medium gives rise to an erosion of metal parts of the apparatus at the liquid solid interface so that the service life of the apparatus is shortened.
It is an object of the present invention to provide in an apparatus for creating acoustic oscillations in a running liquid medium sonic and ultrasonic oscillations at a specified frequency and with maximum amplitude in comparison with component harmonics.